Ginkgo peptide-anti-digestion starch granules and preparation method thereof

Abstract

The invention relates to ginkgo peptide-anti-digestion starch granules and a preparation method thereof, and belongs to the technical field of deep processing of natural products. The method comprises the following steps: (1) preparing ginkgo peptide; (2) uniformly mixing the ginkgo peptide and wheat starch in water; and (3) drying the mixed solution in the step (2) to obtain the ginkgo peptide-anti-digestion starch granules. The preparation process provided by the invention is mild in condition and free of pollution, the obtained ginkgo peptide-anti-digestion starch granules are rich in nutrition, the starch retrogradation degree is remarkably reduced, and the ginkgo peptide-anti-digestion starch granules have relatively high enzymatic degradation resistance and are expected to be applied to development of functional foods for preventing and treating diabetes.

Description

Technical Field

[0001] The present invention relates to the technical field of deep processing of natural products, and in particular to ginkgo peptide-digestion-resistant starch granules and a preparation method thereof. Background Art

[0002] With the continued development of my country's economy, people's living standards have significantly improved, placing higher demands on food safety and nutritional value. At the same time, the incidence of non-communicable chronic diseases and metabolic syndrome, which are closely related to improper diet and lifestyle habits, has risen sharply. Diabetes has become a serious health threat to the Chinese people.

[0003] Research shows that high blood sugar levels after meals are a major contributing factor to the development, exacerbation, and complications of diabetes. Based on their digestion rate, starch can be divided into three main categories: rapidly digestible starch (RDS), which is digested and absorbed in the mouth and small intestine within 20 minutes; slowly digestible starch (SDS), which is completely digested and absorbed in the small intestine within 20 to 120 minutes; and resistant starch (RS), which cannot be digested and absorbed in the small intestine within 120 minutes and is ultimately fermented and utilized by microorganisms in the colon.

[0004] Wheat starch, a major component of the Chinese diet, is rich in nutrients and an important source of energy. However, wheat starch contains a high content of rapidly digestible starch (RDS). Long-term or frequent intake of excessive amounts of rapidly digestible starch can easily lead to a decrease in the body's sensitivity to insulin, thereby increasing the risk of type 2 diabetes. Compared with RDS, foods high in resistant starch (RS) can not only effectively maintain satiety and promote intestinal motility, but can also be fermented in the colon to produce large amounts of short-chain fatty acids, which help improve the intestinal microenvironment and increase the diversity of intestinal microbial flora, which is of great benefit to maintaining human health. Therefore, the research and development of functional starches with anti-digestive properties has become one of the hot topics in food science research at home and abroad.

[0005] In recent years, domestic and foreign scholars and enterprise technicians have carried out a lot of research and development work on how to reduce the oil content of French fries: Xiao Jianhui and Niu Liya have disclosed a method for preparing protein peptide-slowly digestible starch granules (Patent No. CN107802001B). Using rice starch as the primary raw material, protein peptides are added as an ingredient, followed by homogenization and spray drying to produce the granules. The method involves only the raw rice starch, the protein peptides as an ingredient, and water, and involves performing a composite physical modification on the rice starch. Compared to single physical modification, the resulting protein peptide-slowly digestible starch granules are more nutritious, with a protein content of up to 15% by weight and a slowly digestible starch content of up to 56% by weight.

[0006] Hong Yan, Li Wendong and others disclosed a processing technology for increasing the digestion resistance of corn flour (patent number: CN115736171B). This method retains the protein in the corn kernels as much as possible during the extraction process of corn flour, removes cellulose that affects the taste, and produces corn flour with a tight combination of starch and protein. The digestibility of starch in the product is reduced by a combined ultrasonic-heat treatment method, so that the total content of slowly digestible starch and resistant starch can be above 50%.

[0007] In summary, the addition of protein and its hydrolysates has great potential for improving starch digestion. However, different types of starch have different digestibility characteristics, and protein hydrolysates from different sources have different properties and structures, thus affecting starch digestion differently. The question of how to obtain wheat starch with digestion-resistant properties remains unanswered. Summary of the Invention

[0008] The present invention aims to provide a ginkgo peptide-digestion-resistant starch granule and a preparation method thereof. The method has simple process conditions, is easy to control, is highly safe, and the prepared starch granules have strong digestion resistance.

[0009] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The invention provides a preparation method of ginkgo peptide-digestion-resistant starch granules, comprising the following steps: 1. preparing ginkgo peptide; 2. uniformly mixing ginkgo peptide and wheat starch in water; and 3. drying the mixed solution in step 2 to obtain ginkgo peptide-digestion-resistant starch granules.

[0010] Preferably, the ginkgo peptide described in step ① is obtained by hydrolyzing ginkgo protein isolate with Alacase enzyme.

[0011] Preferably, the molecular weight of the ginkgo peptide in step ① is less than 1000 Daltons, and the solubility of the ginkgo peptide is greater than 95%.

[0012] Preferably, the ginkgo peptide in step ① should contain at least one of the following sequences: PGPPSD, VIPQLH, EVVMN, SDNFVKL, AQEPTQR, SDSPIR, LIVKVERG, PTMAY, QTYRPF, etc.

[0013] Preferably, the ginkgo peptide described in step ② is 5-100% of the mass of wheat starch.

[0014] Preferably, the solid content of the mixed solution in step ② is 10-50%, the mixing temperature is 20-45° C., and the mixing time is 1-3 h.

[0015] Preferably, the mixed solution in step ② is gelatinized at a gelatinization temperature of 90-100° C. and a gelatinization time of 10-40 min.

[0016] Preferably, the drying method in step ③ is freeze-drying, and after sufficient drying, the mixture is crushed and sieved to obtain ginkgo peptide-resistant starch granules.

[0017] The present invention also provides ginkgo peptide-digestion-resistant starch granules prepared by the above method, wherein the polypeptide content in the ginkgo peptide-digestion-resistant starch granules is 5-50%, and the digestion-resistant starch content is 50-60%.

[0018] Beneficial effects of the present invention: (1) The ginkgo peptide-resistant starch granule product provided by the present invention mainly uses wheat starch and ginkgo peptide as raw materials, adds exogenous ginkgo peptide, mixes and gelatinizes, and then obtains ginkgo peptide-resistant starch granules by freeze-drying, crushing and sieving. The whole process is mild and does not involve the use of strong acid or strong alkali to treat rice starch. Therefore, the production process is pollution-free and environmentally friendly.

[0019] (2) In the ginkgo peptide-resistant starch granule product described in the present invention, the small molecule peptide can bind to the wheat starch molecules through non-covalent interactions such as hydrogen bonding and hydrophobic interactions, and can be effectively wrapped on the starch surface, affecting the swelling and gelatinization properties of the starch, reducing the content of rapidly digestible starch in the wheat starch, and increasing the content of resistant starch in the wheat starch. At the same time, ginkgo peptide has a certain inhibitory effect on amylase. The above two effects synergistically can effectively reduce the digestion rate of wheat starch. In addition, ginkgo peptide itself also has antioxidant, anti-glycation, and blood pressure lowering effects. Therefore, the use of ginkgo peptide and wheat starch together may also give the product a variety of biological activities.

[0020] (3) The ginkgo peptide-resistant starch granule product of the present invention has a high content of resistant starch, which can effectively enhance satiety and reduce the desire to eat. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings: Figure 1 RVA diagram of wheat starch-different addition amounts of ginkgo peptide (GBP) Figure 2 Scanning electron micrograph of wheat starch without ginkgo peptide added Figure 3 Scanning electron microscope image of ginkgo peptide-resistant starch granules (the mass ratio of ginkgo peptide to starch is 1:1) DETAILED DESCRIPTION

[0022] The following examples are some examples of the present invention and should not be considered as limiting the present invention.

[0023] Determination of starch digestibility: Mix 200 mg of sample with 15 mL of sodium acetate buffer (pH 5.2) and incubate at 37°C for 30 min. Simultaneously, prepare a mixed enzyme solution containing 150 U / mL of α-amylase and 80 U / mL of saccharifying enzyme. Add 10 mL of the enzyme solution and incubate at 37°C with constant agitation. Samples are collected at 0, 20, and 120 minutes, mixed with anhydrous ethanol, and centrifuged. Glucose content is measured using a glucose oxidase kit. RDS, SDS, and RS contents are calculated using the following formulas: Where, M s represents the content of wheat starch in the sample; M c0, M c20 and M c120 represents the amount of glucose produced at 0, 20, and 120 min, respectively.

[0024] The gelatinization properties of the sample were tested using a rapid viscosity analyzer in accordance with GB / T 24853-2010.

[0025] Example 1 Ginkgo protein isolate was prepared using an alkaline dissolution and isoelectric precipitation method. The dried ginkgo protein isolate was evenly dispersed in distilled water to a protein concentration of 10%. The system temperature was adjusted to 50°C and the pH to 8.0. Alcalase was added at an enzyme-substrate ratio of 1:50. After hydrolysis for 4 hours, insoluble matter was removed by centrifugation. The hydrolyzate was freeze-dried and redissolved in water. Ginkgo peptides with a molecular weight of less than 1000 Daltons were obtained by ultrafiltration.

[0026] Pipette 25 mL of distilled water into a dry and clean sample barrel, add 3 g of wheat starch and a certain amount of ginkgo peptide, mix thoroughly, and use a rapid viscosity analyzer to measure the effect of ginkgo peptide on the gelatinization properties of wheat starch. Record the viscosity change curve of the starch gelatinization process, record the gelatinization temperature, peak viscosity, peak time, minimum viscosity, final viscosity, attenuation value, and recovery value. The results are shown in Figure 1 .

[0027] Table 1 Effects of different ginkgo peptide contents on the gelatinization properties of wheat starch sample Peak viscosity (cP) Minimum viscosity (cP) Final viscosity (cP) Attenuation value (cP) Regeneration value (cP) Gelatinization temperature (℃) starch <![CDATA[2688.33 ± 29.56 a ]]> <![CDATA[2213.33 ± 17.99 a ]]> <![CDATA[3110.67 ± 38.13 a ]]> <![CDATA[475.00 ± 12.25 a ]]> <![CDATA[897.33 ± 20.14 a ]]> <![CDATA[87.70 ± 0.36 c ]]> Starch + 5% ginkgo peptide <![CDATA[2638.00 ± 31.21 ab ]]> <![CDATA[2190.33 ± 28.12 a ]]> <![CDATA[3088.33 ± 37.82 a ]]> <![CDATA[447.67 ± 25.85 a ]]> <![CDATA[898.00 ± 24.10 a ]]> <![CDATA[87.70 ± 0.43 c ]]> Starch + 10% ginkgo peptide <![CDATA[2590.00 ± 39.90 b ]]> <![CDATA[2119.00 ± 30.24 b ]]> <![CDATA[3060.33 ± 46.02 a ]]> <![CDATA[471.00 ± 14.51 a ]]> <![CDATA[941.33 ± 22.23 a ]]> <![CDATA[87.42 ± 0.41 c ]]> Starch + 25% ginkgo peptide <![CDATA[2491.33 ± 12.68 c ]]> <![CDATA[2008.67 ± 8.26 c ]]> <![CDATA[2913.33 ± 3.09 b ]]> <![CDATA[482.67 ± 4.92 a ]]> <![CDATA[904.67 ± 10.34 a ]]> <![CDATA[88.77 ± 0.02 b ]]> Starch + 50% ginkgo peptide <![CDATA[2416.06 ± 30.65 cd ]]> <![CDATA[2068.48 ± 16.05 bc ]]> <![CDATA[2690.30 ± 43.48 c ]]> <![CDATA[347.58 ± 15.11 b ]]> <![CDATA[621.82 ± 30.54 b ]]> <![CDATA[89.28 ± 0.45 b ]]> Starch + 100% ginkgo peptide <![CDATA[2340.33 ± 69.50 d ]]> <![CDATA[2089.67 ± 40.61 b ]]> <![CDATA[2500.00 ± 70.00 d ]]> <![CDATA[250.67 ± 29.01 c ]]> <![CDATA[410.33 ± 29.53 c ]]> <![CDATA[92.58 ± 0.34 a ]]> Example

[0028] Ginkgo biloba protein isolate was prepared using an alkaline dissolution and isoelectric precipitation method. Dried ginkgo biloba protein isolate was uniformly dispersed in distilled water to a protein concentration of 10%. The system temperature was adjusted to 50°C and the pH to 8.0. Alcalase was added at an enzyme-substrate ratio of 1:50. After hydrolysis for 4 hours, insoluble matter was removed by centrifugation. The hydrolyzate was freeze-dried and redissolved in water. Ginkgo biloba peptides with a molecular weight of less than 1000 Da were obtained by ultrafiltration. High-resolution liquid chromatography-mass spectrometry revealed that the ginkgo biloba peptides contained peptides including PGPPSD, VIPQLH, EVVMN, SDNFVKL, AQEPTQR, SDSPIR, LIVKVERG, PTMAY, and QTYRPF.

[0029] 5 g of ginkgo peptide was evenly dispersed in 100 mL of water at 40°C. Once fully dissolved, 10 g of wheat starch was added and stirred for 1.5 hours. The mixture was heated to 95°C and gelatinized for 20 minutes. After cooling to room temperature, the sample was freeze-dried, crushed, and sieved to obtain ginkgo peptide-resistant starch granules. The product prepared by this method had a resistant starch (RS) content of 60.83%.

[0030] Example 3 Ginkgo protein isolate was prepared using an alkaline dissolution and isoelectric precipitation method. The dried ginkgo protein isolate was evenly dispersed in distilled water to a protein concentration of 10%. The system temperature was adjusted to 50°C and the pH to 8.0. Alcalase was added at an enzyme-substrate ratio of 1:50. After hydrolysis for 4 hours, insoluble matter was removed by centrifugation. The hydrolyzate was freeze-dried and redissolved in water. Ginkgo peptides with a molecular weight of less than 1000 Daltons were obtained by ultrafiltration.

[0031] 10 g of ginkgo peptide was evenly dispersed in 100 mL of water at 50°C. Once fully dissolved, 10 g of wheat starch was added and stirred for 1 hour. The mixture was heated to 95°C and gelatinized for 20 minutes. After cooling to room temperature, the sample was freeze-dried, crushed, and sieved to obtain ginkgo peptide-resistant starch granules. The product prepared by this method had a resistant starch (RS) content of 67.36%.

[0032] Comparative Example 1 Disperse 10 g of wheat starch in 100 mL of water at 50°C and stir for 1 hour. Heat the mixture to 95°C and gelatinize for 20 minutes. After cooling to room temperature, the sample is freeze-dried, crushed, and sieved to form gelatinized starch granules. Testing shows that the product prepared by this method has a digestibility-resistant starch (RS) content of 50.56%.

[0033] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for preparing ginkgo peptide-digestion-resistant starch granules, comprising the following steps: ①Preparation of ginkgo peptide; ② Evenly mix ginkgo peptide and wheat starch in water; ③ Dry the mixed solution in step ② to obtain ginkgo peptide-digestion-resistant starch granules.

2. The preparation method according to claim 1, characterized in that The ginkgo peptide described in step ① is obtained by hydrolyzing ginkgo protein isolate by Alacase enzyme.

3. The preparation method according to claim 1, characterized in that The molecular weight of the ginkgo peptide described in step ① is less than 1000 Daltons, and the solubility of the ginkgo peptide is greater than 95%.

4. The preparation method according to claim 1, characterized in that The ginkgo peptide described in step ① should contain at least one of the following sequences: PGPPSD, VIPQLH, EVVMN, SDNFVKL, AQEPTQR, SDSPIR, LIVKVERG, PTMAY, QTYRPF, etc.

5. The preparation method according to claim 1, characterized in that The ginkgo peptide described in step ② is 5-100% of the mass of wheat starch.

6. The preparation method according to claim 1, characterized in that The solid content of the mixed solution in step ② is 10-50%, the mixing temperature is 20-50°C, and the mixing time is 1-3 hours.

7. The preparation method according to claim 1, characterized in that The mixed solution described in step ② is gelatinized at a gelatinization temperature of 90-100°C and a gelatinization time of 10-40 min.

8. The preparation method according to claim 1, characterized in that The drying method described in step ③ is freeze drying, and after sufficient drying, the mixture is crushed and sieved to obtain ginkgo peptide-resistant starch granules.

9. The ginkgo peptide-digestion-resistant starch granules obtained by the preparation method according to any one of claims 1 to 8, wherein the polypeptide content in the ginkgo peptide-digestion-resistant starch granules is 5-50%, and the digestion-resistant starch content is 50-60%.

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